Tuesday, May 19, 2009

Climate Change Odds Much Worse Than Thought

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" ... the MIT model is the only one that interactively includes detailed treatment of possible changes in human activities as well - such as the degree of economic growth, with its associated energy use, in different countries."
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News Release
Massachusetts Institute of Technology
May 19, 2009

Climate change odds much worse than thought

New analysis shows warming could be double previous estimates

David Chandler, MIT News Office

The most comprehensive modeling yet carried out on the likelihood of how much hotter the Earth's climate will get in this century shows that without rapid and massive action, the problem will be about twice as severe as previously estimated six years ago - and could be even worse than that.

The study uses the MIT Integrated Global Systems Model, a detailed computer simulation of global economic activity and climate processes that has been developed and refined by the Joint Program on the Science and Policy of Global Change since the early 1990s. The new research involved 400 runs of the model with each run using slight variations in input parameters, selected so that each run has about an equal probability of being correct based on present observations and knowledge. Other research groups have estimated the probabilities of various outcomes, based on variations in the physical response of the climate system itself. But the MIT model is the only one that interactively includes detailed treatment of possible changes in human activities as well - such as the degree of economic growth, with its associated energy use, in different countries.

Study co-author Ronald Prinn, the co-director of the Joint Program and director of MIT's Center for Global Change Science, says that, regarding global warming, it is important "to base our opinions and policies on the peer-reviewed science," he says. And in the peer-reviewed literature, the MIT model, unlike any other, looks in great detail at the effects of economic activity coupled with the effects of atmospheric, oceanic and biological systems. "In that sense, our work is unique," he says.

The new projections, published this month in the American Meteorological Society's Journal of Climate, indicate a median probability of surface warming of 5.2 degrees Celsius by 2100, with a 90% probability range of 3.5 to 7.4 degrees. This can be compared to a median projected increase in the 2003 study of just 2.4 degrees. The difference is caused by several factors rather than any single big change. Among these are improved economic modeling and newer economic data showing less chance of low emissions than had been projected in the earlier scenarios. Other changes include accounting for the past masking of underlying warming by the cooling induced by 20th century volcanoes, and for emissions of soot, which can add to the warming effect. In addition, measurements of deep ocean temperature rises, which enable estimates of how fast heat and carbon dioxide are removed from the atmosphere and transferred to the ocean depths, imply lower transfer rates than previously estimated.

Prinn says these and a variety of other changes based on new measurements and new analyses changed the odds on what could be expected in this century in the "no policy" scenarios - that is, where there are no policies in place that specifically induce reductions in greenhouse gas emissions. Overall, the changes "unfortunately largely summed up all in the same direction," he says. "Overall, they stacked up so they caused more projected global warming."

While the outcomes in the "no policy" projections now look much worse than before, there is less change from previous work in the projected outcomes if strong policies are put in place now to drastically curb greenhouse gas emissions. Without action, "there is significantly more risk than we previously estimated," Prinn says. "This increases the urgency for significant policy action."
To illustrate the range of probabilities revealed by the 400 simulations, Prinn and the team produced a "roulette wheel" that reflects the latest relative odds of various levels of temperature rise. The wheel provides a very graphic representation of just how serious the potential climate impacts are.

"There's no way the world can or should take these risks," Prinn says. And the odds indicated by this modeling may actually understate the problem, because the model does not fully incorporate other positive feedbacks that can occur, for example, if increased temperatures caused a large-scale melting of permafrost in arctic regions and subsequent release of large quantities of methane, a very potent greenhouse gas. Including that feedback "is just going to make it worse," Prinn says.

The lead author of the paper describing the new projections is Andrei Sokolov, research scientist in the Joint Program. Other authors, besides Sokolov and Prinn, include Peter H. Stone, Chris E. Forest, Sergey Paltsev, Adam Schlosser, Stephanie Dutkiewicz, John Reilly, Marcus Sarofim, Chien Wang and Henry D. Jacoby, all of the MIT Joint Program on the Science and Policy of Global Change, as well as Mort Webster of MIT's Engineering Systems Division and D. Kicklighter, B. Felzer and J. Melillo of the Marine Biological Laboratory at Woods Hole.
Prinn stresses that the computer models are built to match the known conditions, processes and past history of the relevant human and natural systems, and the researchers are therefore dependent on the accuracy of this current knowledge. Beyond this, "we do the research, and let the results fall where they may," he says. Since there are so many uncertainties, especially with regard to what human beings will choose to do and how large the climate response will be, "we don't pretend we can do it accurately. Instead, we do these 400 runs and look at the spread of the odds."

Because vehicles last for years, and buildings and powerplants last for decades, it is essential to start making major changes through adoption of significant national and international policies as soon as possible, Prinn says. "The least-cost option to lower the risk is to start now and steadily transform the global energy system over the coming decades to low or zero greenhouse gas-emitting technologies."

This work was supported in part by grants from the Office of Science of the U.S. Dept. of Energy, and by the industrial and foundation sponsors of the MIT Joint Program on the Science and Policy of Global Change.

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Sunday, February 15, 2009

Eating less meat could cut climate costs

Submitted by Alexandra Paul

Cutting back on beefburgers and bacon could wipe $20 trillion off the cost of fighting climate change. That's the dramatic conclusion of a study that totted up the economic costs of modern meat-heavy diets.

The researchers involved say that reducing our intake of beef and pork would lead to the creation of a huge new carbon sink, as vegetation would thrive on unused farmland.

The model takes into account farmland that is used to grow extra food to make up for the lost meat, but that requires less area, so some will be abandoned. Millions of tonnes of methane, a potent greenhouse gas, would also be saved every year due to reduced emissions from farms.

These impacts would lessen the need for expensive carbon-saving technologies, such as "clean coal" power plants, and so save huge sums, say Elke Stehfest of the Netherlands Environmental Assessment Agency and colleagues.
Flatulent feeders

Climate-change experts have warned of the high carbon cost of meat for several years.

Beef is particularly damaging. Methane, a potent greenhouse gas, is released from flatulent cows and by manure as it decays. Furthermore, to produce a kilogram of beef (2.2 pounds), farmers also have to feed a cow 15 kg of grain and 30 kg of forage. Grain requires fertiliser, which is energy intensive to produce.

Stehfest has now weighed the economic impact of beef and other meats against the cost of stabilising carbon dioxide levels at 450 parts per million – a level that some scientists say is needed to help prevent dangerous droughts and sea level rises.

If eating habits do not change, Stehfest estimates that emissions would have to be cut by two-thirds by 2050, which is likely to cost around $40 trillion.

If, however, the global population shifted to a low-meat diet – defined as 70 grams of beef and 325 grams of chicken and eggs per week – around 15 million square kilometres of farmland would be freed up. Vegetation growing on this land would mop up carbon dioxide. It could alternatively be used to grow bioenergy crops, which would displace fossil fuels.
Supermarket labels

Greenhouse gas emissions would also fall by 10% due to the drop in livestock numbers, she calculates. Together, these impacts would halve the costs of dealing with climate change by 2050.

To help consumers, the environmental cost of meat, in terms of carbon emissions per portion, could also be included in the purchase price, says Stehfest.

The costs sound about right, says Raymond Desjardins of Agriculture and Agri-Food Canada. However, it may be unfair to compare future farms to current ones, he adds.

New Scientist 2-10-09

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Thursday, January 22, 2009

Meat just doesn't cut it in today's environment

The Georgia Straight (Vancouver)
January 21, 2009

By Dave Steele

There's little doubt about it. Humans evolved as omnivores. The shapes of our teeth, the lengths of our intestines, and a wealth of fossil evidence (arrowheads, butchered animal bones, et cetera) all point to an omnivorous past.

Natural selection favoured meat eating because it allowed our ancestors to survive where edible plant supplies were in short supply. Our forebears could flourish on fruits and grains and berries when those were plentiful and switch to meat when edible plants were scarce. Had early humans not led omnivorous lives, they almost certainly would have died out.

But that was then. This is now.

In the past, humans were few and far between. The pressure we exerted on the world around us was slight. Today, with our population approaching seven billion, the pressures we exert are enormous. No longer a boon to humanity, our hunger for meat has become the single biggest contributor to planetary degradation. Be it global warming, fossil-fuel depletion, water depletion or desertification, meat consumption is a prime factor in the problem. And meat takes food out of the mouths of the hungry.

On today's factory farms, it takes 2.4 pounds of dry corn, soy, and oats to produce a pound of chicken; eight to 10 pounds of similar feed is required for every pound of beef. According to Cornell University's David Pimentel, nearly 800 million people could fill their stomachs for a year on the grain fed to U.S. animals alone. And that's just the tip of the iceberg.

According to Pimentel's careful reckoning, modern western diets could not exist at all were it not for the enormous amount of fossil fuels we pour into them. Just getting nitrogen into our fertilizers takes the equivalent of nearly one million barrels of oil each day. Add in the other components-the pesticides, the herbicides, the combines, the tractors, and all the rest-and the numbers become astronomical. As Pimentel shows, the way we raise meat, it takes some 28 calories of fossil fuel input to generate one calorie of food value. Even modern lacto-ovo vegetarian diets, he warns, can't be maintained in our world without excessive amounts of oil and gas.

Meat production accelerates global warming, too. All those burned fossil fuels have to go somewhere. Worse, our cows and sheep and other ruminants emit methane as they digest their feed. Together, Canada's 10 million cows release the methane equivalent of a half ton of CO2 for every man, woman, and child in the country. According to the UN Food and Agriculture Organization, animal agriculture is responsible for a bigger share of global warming than all of the cars and trucks and ships and planes in the world combined!

And animal agriculture emits other pollutants, too. Nearly three-quarters of North American ammonia emissions are due directly or indirectly to animal farming. Manure contaminates our ground water. The Worldwatch Institute reports that farm animals in the United States generate 130 times more bodily waste than humans.

Animal agriculture destroys land and habitat, too. Raising livestock and the soybeans to feed them is easily the biggest contributor to rainforest destruction. More than two acres of tropical rainforest are cleared per second to graze or feed farm animals. Around the world, tens of billions of tons of topsoil are lost each year to cultivation of animal feed crops.

Fish are no solution either. We've mined the oceans so badly that almost all of the world's fisheries are in serious decline. Hunting? Sorry. All of North America's wildlife would be wiped out were we to satisfy our current hunger for meat that way.

In the past, the meat eating was a boon to us. But today, the opposite is true. Natural selection operates on the here and now. If we don't curtail our consumption of meat and eggs and milk and cheese, natural selection will eventually work in the strongest way against our meat-eating habits.

But we're lucky. We evolved as omnivores. We can choose what we eat. Plants or animals.
Choose plants. There's an awful lot at stake.

Dave Steele is the vice president of Earthsave Canada http://www.earthsave.ca/

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Tuesday, January 6, 2009

The Low-Carbon Diet

Change your light bulbs? Or your car? If you want to fight global warming, it's time to consider a different diet.

By Mike Tidwell

Full disclosure: I love to eat meat. I was born in Memphis, the barbecue capital of the Milky Way Galaxy. I worship slow-cooked, hickory-smoked pig meat served on a bun with extra sauce and cole slaw spooned on top.

My carnivore's lust goes beyond the DNA level. It's in my soul. Even the cruelty of factory farming doesn't temper my desire, I'll admit. Like most Americans, I can somehow keep at bay all thoughts of what happened to the meat prior to the plate.

So why in the world am I a dedicated vegetarian? Why is meat, including sumptuous pork, a complete stranger to my fork at home and away? The answer is simple: I have an 11-year-old son whose future - like yours and mine - is rapidly unraveling due to global warming. And what we put on our plates can directly accelerate or decelerate the heating trend.

That giant chunk of an Antarctic ice sheet, the one that disintegrated in a matter of hours, the one the size of seven Manhattans - did you hear about it? It shattered barely a year ago "like a hammer on glass," scientists say, and is now melting away in the Southern Ocean. This is just a preview, of course, of the sort of ecological collapse coming everywhere on earth, experts say, unless we hit the brakes soon on climate change. If the entire West Antarctic ice sheet melts, for example, global sea-level rise could reach 20 feet.

Since the twin phenomena of Hurricane Katrina and Hurricane Gore, most Americans have a basic literacy on the issue of climate change. It's getting worse, we know, and greenhouse gases-emitted when we burn fossil fuels-are driving it. Less accepted, it seems, is the role food-specifically our consumption of meat-is playing in this matter. The typical American diet now weighs in at more than 3,700 calories per day, reports the U.N. Food and Agriculture Organization, and is dominated by meat and animal products. As a result, what we put in our mouths now ranks up there with our driving habits and our use of coal-fired electricity in terms of how it affects climate change.

Simply put, raising beef, pigs, sheep, chicken, and eggs is very, very energy intensive. More than half of all the grains grown in America actually go to feed animals, not people, says the World Resources Institute. That means a huge fraction of the petroleum-based herbicides, pesticides, and fertilizers applied to grains, plus staggering percentages of all agricultural land and water use, are put in the service of livestock. Stop eating animals and you use dramatically less fossil fuels, as much as 250 gallons less oil per year for vegans, says Cornell University's David Pimentel, and 160 gallons less for egg-and-cheese-eating vegetarians.

But fossil fuel combustion is just part of the climate-diet equation. Ruminants-cows and sheep-generate a powerful greenhouse gas through their normal digestive processes (think burping and emissions at the other end). What comes out is methane (23 times more powerful at trapping heat than CO2) and nitrous oxide (296 times more powerful).

Indeed, accounting for all factors, livestock production worldwide is responsible for a whopping 18 percent of the world's total greenhouse gases, reports the U.N. Food and Agriculture Organization. That's more than the emissions of all the world's cars, buses, planes, and trains combined.

So why do we so rarely talk about meat consumption when discussing global warming in America? Compact fluorescent bulbs? Biking to work? Buying wind power? We hear it nonstop. But even the super-liberal, Prius-driving, Green Party activist in America typically eats chicken wings and morning bacon like everyone else. While the climate impacts of meat consumption might be new to many people, the knowledge of meat's general ecological harm is not at all novel. So what gives?

Roughly three percent of all Americans are vegetarians, according to the Vegetarian Resource Group, a nonprofit that educates people on the benefits of a meat-free diet. Part of the reason, I know, is the unfortunate belief that vegetarianism is a really tough lifestyle change, much harder than simply changing bulbs or buying a better car. But as a meat lover at heart, I've been a vegetarian (no fish, minimal eggs and cheese) for seven years, and trust me: It's easy, satisfying, and of course super healthy. With the advent of savory tofu, faux meats, and the explosion of local farmers' markets, a life without meat is many times easier today than when Ovid and Thoreau and Gandhi and Einstein did it. True, many meat substitutes are made from soybeans, a mono crop with its own environmental issues. But most soy production today is actually devoted to livestock feed. Only 1 percent of U.S. soybeans become tofu, for example.

One day I get carryout veggie Pad Thai. The next I cook stir-fried veggies at home with soy-based sausage patties so good they fool even the most discriminating meat connoisseurs. Bottom line: Of the most difficult things I've ever done in my life, vegetarianism doesn't even make the chart.

Some folks, I realize, have a deep-down, gut-level (so to speak) reaction to vegetarianism as "unnatural." We humans have canine teeth, after all. We evolved to include meat in our diets. To abandon such food is to break thousands of years of tradition and, in some cases, ritual behavior bordering on the sacred.

All true. But we also evolved as people who defecated indiscriminately in the woods and who didn't brush our teeth. Somehow we've moved to a higher level on those counts. Now, with potentially catastrophic climate change hovering around the corner and with our briskets and London broil helping to drive the process, it's time to evolve some more.

A compromise in recent years, of course, has been the idea of animals raised locally and organically. Becoming a "locavore" who eats regional fruits and vegetables in season as much as possible makes abundant sense, of course. And animals from your area can lower the environmental impacts of your diet in many ways while simultaneously saving cherished local farmland and progressive farm families.

But with global warming, here's the inconvenient truth about meat and dairy products: If you eat them, regardless of their origin and how they were produced, you significantly contribute to climate change. Period. If your beef is from New Zealand or your own backyard, if your lamb is organic free-range or factory farmed, it still has a negative impact on global warming.

This is true for several reasons. Again, the biological reality of ruminant digestion is that methane is released. The feed can be local and organic, but the methane is the same, escaping into the atmosphere and trapping heat with impressive efficiency. Second, no matter the farming method, livestock makes manure that produces nitrous oxide, an even more awesomely impressive heat trapper. Livestock in the United States generates a billion tons of manure per year, accounting for 65 percent of the planet's anthropogenic nitrous oxide emissions.

Even poultry, while less harmful, also contributes. Ironically, data released in 2007 by Adrian Williams of Cranfield University in England show that when all factors are considered, organic, free-range chickens have a 20 percent greater impact on global warming than conventionally raised broiler birds. That's because"sustainable" chickens take longer to raise, and eat more feed. Worse, organic eggs have a 14 percent higher impact on the climate than eggs from caged chickens, according to Williams.

"If we want to fight global warming through the food we buy, then one thing's clear: We have to drastically reduce the meat we consume,"says Tara Garnett of London's Food Climate Research Network.

So while some of us Americans fashionably fret over our food's travel budget and organic content, Garnett says the real question is, "Did it come from an animal or did it not come from an animal?"

Which brings us back to vegetarianism and why I live a meat-free life. The facts speak for themselves. If we really want to fight climate change, we should change our light bulbs and purchase hybrid cars and, above all, vote for politicians committed to a clean energy future. But we should also eat less meat, a lot less, or none at all.

I believe consumer habits are starting to change similarly to the way they've shifted with compact fluorescent bulbs. Ten years ago people complained about the harsh quality of light from fluorescents and the hassle of switching them out. But the bulbs are now made to produce a much warmer quality of light and the price has come down. What's more, in seven years of using only CFLs at my home, I've never had a guest make a single comment.

In the near future, as we increasingly discuss the climate "facts" of meat consumption, and as veggie cuisine gets still easier at home and at restaurants, we'll see more and more people changing their diets in the same way they're switching to CFLs in droves now. Of this I'm sure.

But when it comes to food, the facts are not enough for many people. Of this I'm also sure. A holistic nutritionist in my neighborhood says one's ideas about food reside in the same part of the brain that houses our ideas and beliefs about religion. It's not all rational, in other words. Facts abound about the harm of fatty, sugary foods, yet the obesity epidemic grows. And I can't count the number of environmental conferences I've attended where meat was served in abundance. Even Michael Pollan's 2006 bestseller The Omnivore's Dilemma, wherein he dissects with encyclopedic thoroughness the eco-hazards and animal cruelty issues surrounding meat and egg production-even this book astonishingly mentions the words global warming only two times and climate change not at all. In 464 pages.That's highly unreasonable, in my view.

All of which is to say that for people to care, the climate-food discussion must be about more than just facts, more than pounds of greenhouse gases per units of food. It's got to be about morality, about right versus wrong. And I don't mean the usual morality of environmental "stewardship." Or even the issue of cruelty to farm animals. I'm talking here about cruelty to people, about the explicit harm to humans that results from meat consumption and its role as a driving force in climate change. Knowingly eating food that makes you fat or harms your local fish and birds is one thing. Knowingly eating food that makes children across much of the world hungry is another.

I served as a Peace Corps volunteer in the Democratic Republic of the Congo in the mid-1980s, living in a tiny rural village where the staple crop was hand-tilled corn. It was harvested twice a year, in May and December. This meant the two annual "rainy seasons" had to begin right on time, in January and September, and continue for several months afterward. Any deviation from this rainfall pattern virtually guaranteed a lower corn harvest. And given the total absence of grocery stores, community granaries, or the money to buy extra food even if it existed, this meant hunger.

A signature impact of global warming, of course, is a dramatic shift in precipitation patterns worldwide, including longer and more severe droughts as well as extreme rainstorms and flooding in non-drought areas. Many scientists believe these impacts are already being felt by farmers worldwide and could spell future disaster, especially for subsistence farmers like those I lived with in Africa. Global wheat prices have jumped about 100 percent in the past year in part because a record drought in Australia-made worse by global warming-has devastated farmers across the continent. Food production in China alone could drop 10 percent as early as 2030, United Nations scientists warn.

The people I lived with in Africa contribute almost nothing to the problem of global warming, through their diet or otherwise. Coal-fired electricity versus wind power? They don't have electricity. SUVs versus hybrid cars? They don't have cars-none at all, or roads for that matter. And meat consumption? Tiny, tiny portions maybe twice a week.

If we in the West don't alter course in the coming years, if we allow extreme global warming to become reality, an impact on the U.S. diet could very well be a great reduction in the amount of meat on our tables-a reduction imposed on us by nature instead of achieved by us through enlightened lifestyle changes. The wide and guaranteed availability of agriculturally productive land may simply cease. The crop yields we see now could shrink significantly, thanks to everything from weird weather to pest invasions. But it's a safe guess to say we'll have space for a national diet of plant-based foods (some crops are expected to benefit from global warming), just not the option of consuming all those animals.

But in the Congo and other poor countries, in places like Bangladesh and Peru and Vietnam, where meat consumption is already low, severe climate change means food off the table. It means hungry children. It means the rains don't come on time or at all in tiny villages like the one I lived in. It means, in the end, cruelty to people.

Are we clear now on the raw facts and urgent morality of our present meat consumption in America?

We need much more than just a few magazine readers to voluntarily stop eating meat, of course. It's a good start, but what we really need are national policies that encourage lower meat consumption by everyone. This could be achieved using fees or other market mechanisms that properly price greenhouse-gas emissions according to the harm they cause. The bad news, I suppose, is that the cost of meat could rise. The good news is we would finally have a fair and honest way to judge its danger, and thus more incentives to do the right thing, more incentives to switch to a healthy and convenient vegetarian diet of the sort I've joyfully embraced for years, despite my great appreciation for the taste of meat.

We could also, as a nation, just eat a lot less meat as an alternative to full vegetarianism. Anthony McMichael, a leading Australia-based expert on climate change and health issues, has crunched the numbers. He estimates that per capita daily meat consumption would need to drop from about 12 ounces per day in America to 3.1 ounces (with less than half of it red meat) in order to protect the climate.

I suppose I could measure out 3.1 ounces of meat per day, cook it, eat it, and still feel morally okay. But frankly I'd rather just go without. I'd rather be a vegetarian. It's easier to explain. It's easier to defend. And I just plain like it.

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- Mike Tidwell, director of the Chesapeake Climate Action Network, is the author of The Ravaging Tide: Strange Weather, Future Katrinas,and the Coming Death of America's Coastal Cities (Free Press).

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